Water tube boiler



July 10, 1934. HARTER 1,966,388

- WATER TUBE BOILER Filed Oct. 20, 1930 2 Sheets-Sheet l INVENTOR saac Ha/rter ATTORNEY July 10, 1934; AR ER 1,966,388

WATER TUBE BOILER Filed Oct. 20, 1930 2 Sheets-Sheet 2 INVENTOR 1 IsaacHm *Em Fa am ATT RNEY Patented July 10, 1934 UNITED STATES PATENT OFFICEWATER TUBE BOILER Application October 20, 1980, Serial No. 489,833

' 9 Claims (c1. 122-302) This invention relates to water tube boilers,and. more particularly to an arrangement of tubes for such boilers.

An object of the invention is to provide a steam boiler of the type setforth having the tubes thereof arranged so as to produce greaterligament strength in the boiler drum for a given number of tubes thanhas heretofore been possible for the same thickness and diameter ofboiler drum.

Other objects will be apparent to those skilled in this particular artfrom the description in the specification in connection with thedrawings, in which- Fig. 1 is an end view of a section of the drum andtube banks; I

Fig. 2 is a view at right angles to Fig. 1 taken along the line 2-2;

Fig. 3 is a view at right angles to Fig. 1 taken along the line 33;

Fig. 4 is a view at right angles to Fig. along the line 44;

Fig. 5 is an end view similar to Fig. 1 showing a modification of theinvention;

2 Fig. 6 is a view at right angles to Fig. 5 taken along the line 6-6;

Fig. 7 is a view at right angles to Fig. 5 taken along the line 77;

Fig. 8 is a View at right angles to Fig. 5 taken along the line 8-8.

The particular embodiment of the present invention which has been chosenfor the purpose of illustration is shown in connection with a steamboiler of the Stirling type having two upper drums 1 connected by steamand water circulators 2 and 3 respectively, and having banks of tubesconnected therewith.

In order to produce the greatest ligament strength possible in the drumsbetween tubes, the present invention provides an arrangement in whichthe tubes of any given longitudinal row are connected with tube holes inthe drum which are spaced apart a greater distance, longitudinally, ofthe drum than the tubes themselves.

1 taken The tube holes are arranged so as to permit a plurality of tubesof a given longitudinal row to be connected to a plurality of tube holesarranged in a single circumferential row in the drum.

As illustrated in Figs. 1 and 3, the first two longitudinal rows oftubes 4 in the front bank of the boiler are grouped and connected bysuitable connectors with tube holes in the drum. These tube holes arespaced apart longitudinally, a dis- I tance equal to three times thedistance between the separate tubes of a longitudinal row so that theligament between the tube holes longitudinally is at least three timeswhat it would be in a drum having the same number of tubes connectedthereto in the usual way. Each adjacent pair of tubes 4 in the two frontrows of the first bank is connected by Y fittings 6 to a singleconnector 8 joining the fitting to the associated drum, as shown in Fig.1.

Each group of three connectors 8 is expanded into three tube holeslocated in a single circumferential row in the drum as shown in Fig. 3,and it will be apparent that each circumferential row of tube holes isspaced longitudinally from the adjacent rows a distance equal to threetimes the 7 distance longitudinally of the drum between adjacentconnectors 8, resulting in a large increase in the ligament strength ofthe drum over that which would be obtained if the tubes 4 were connecteddirectly to-the drum in the usual manner, or that which would beobtained if the connectors 8 were connected directly to the drum in thesame longitudinal row.

. The tubes 5 forming successive rows of the front bank are connected tothe drum in a slightly so different way which, however, produces asimilar advantageous increase in ligament strength. As illustrated, inFigs. 1 and 4, each pair of tubes 5 in adjacent rows is connected by Yfittings 6' to connectors 7 leading from the fittings to the 5 drum.Alternate connectors [are bent so as to enter the drum through tubeholes'located in the same circumferential row as the tube holesconnected to the intermediate connectors, as shown in Fig. 4. As aresult of this arrangement the longitudinal ligaments in the drum arematerially greater than would be the case if the tubes 5 and connectors7 extended directly to the drum in the usual manner.

Tubes '9 are arranged as risers connecting water walls (not shown) withthe front drum 1.

In order to provide for the greatest possible ligament strengthbetweenthe tube holes in which the risers are expanded, pairs of riser tubesare bent to enter the drum through holes located in the samecircumferential row, the arrangement being such that single intermediateriser tubes, located between each of such pairsof tubes, are connectedto the drum in the usual manner, as

illustrated in Fig. 2. It will be apparent that this results in aconsiderable increase in the ligment strength. a

In the modifications shown in Figs. 5 to 8 similar results areaccomplished by more or less similar arrangements, the difference inconstrucdrum a distance greater than the distance be-' tween successiveconnectors 18 of a given row, and the tube holes are arranged indifferent circumferential rows so as to accommodate all the connectorsof a given row within the length of such row. As illustrated in Figs. 5and '7, the difierent connectors 18 are bent to enter tube holes in thesame circumferential row with adjacent connectors so that the ligamentsbetween holes of adjacent circumferential rows are materially greaterthan the distance between the respective connectors 18.

Each pair of tubes in the subsequent rows of tubes 15 in the front bankis connected to Y fittings 16 which are connected by connectors 17 tothe drum and it will be apparent that the use of the Y fittings inconnection with pairs of tubes in a single longitudinal row provides anarrangement in which tubes of a given row are expanded into half thenumber of tube holes, again resulting in increased ligament strength.The risers 19 from the water walls are connected to the drum in the samemanner as the risers 9 heretofore described.

The tubes of the banks 5 and 15 are normally spaced and given such asize and surface as are most suitable for external conditions incidentto absorbing heat from the passing gases, and when so proportioned areusually of greater internal cross sectional area than is needed for theflow of water through them. Under such conditions it is permissible, sofar as internal circulation is concerned, to reduce the flow area at theupper ends, and highly desirable to do so by means of this invention inthe interests of the drum. Joining the drum to each pair of tubes by onesmaller tube and the Y fittings, reduces the required hole size andnumber in the drum. This permits an increase of ligament strengthbetween holes, or a reduction of drum thickness, or a reduction of drumdiameter, or any two of these or all three of them.

Although I have described the invention as applied to the front bank oftubes of a Stirling type of boiler it will be apparent that it isequally applicable to banks of tubes in other locations and to variousother types of vapor generators. It will also be apparent that thepresent invention is independent of the use of the I fittings which havebeen described in connection with the particular embodiment illustratedin the drawings,

that the invention is equally applicable to boilers in which tubes areunconnected by means of such fittings. For example, the upper ends ofsingle tubes can be arranged in the manner in which the connectors '7,8, 1'7 and 18 are themselves arranged for the purpose of providing thedesired increase in ligament strength.

I claim:

1. In a boiler of the class described, a boiler drum, a plurality oftubes, Y-fittings connecting adjacent pairs of tubes, tubes connectingsaid fittings with tube holes in said drum, said connecting tubes in agiven longitudinal row being connected to tube holes arranged insuccessive circumferential rows.

2. In a fiuid heater, a drum, a bank of fluid heating tubes arranged inrows extending longitudinally and transversely relative to said drum,means connecting certain adjacent tubes in the same transverse row,connector tubes connecting said means with tube holes arranged incircumferential rows spaced longitudinally of said drum, certainadjacent connector tubes in the same longitudinal row being connected totube holes in the same circumferential row, and certain adjacentconnector tubes in the same trans verse row being connected to tubeholes in the same circumferential row.

3. In a fluid heater, a drum, a bank of fluid heating tubes arranged inrows extending longitudinally and transversely relative to said drum,means separately connecting certain adjacent tubes in the sametransverse row, connector tubes connecting said means with tube holesarranged in circumferential rows spaced longitudinally of said drum, andcertain adjacent connector' tubes in the same transverse row beingconnected to tube holes in the same circumferential row.

4. In a fluid heater, a drum, a bank of substantially vertical fluidheating tubes arranged in rows extending longitudinally and transverselyrelative to said drum, means separately connecting certain pairs ofadjacent tubes in the same transverse row, connector tubes separatelyconnecting said means with tube holes arranged in circumferential rowsspaced longitudinally of said drum, and certain adjacent connector tubesin the same longitudinal row being connected to tube holes in the samecircumferential row.

certain adjacent connector tubes in the same' transverse row beingconnected to tube holes in different circumferential rows.

6. In a fluid heater, a drum, a bank of fluid heating tubes arranged inrows extending longitudinally and transversely relative to said drum,'

means connecting certain adjacent tubes in the same longitudinal row,connector tubes connecting said means with tube holes arranged incircumferential rows spaced longitudinally of said drum, and certainadjacent connector tubes in' the same longitudinal row being connectedto tube holes in the same circumferential row.

'7. In a fluid heater, a drum, a bank of fiuid heating tubes arranged inrows extending longitudinally and transversely relative to said drum,

means connecting certain adjacent tubes in the same longitudinal? row,connector tubes connecting said means with tube holes arranged incircumferential rows spaced longitudinally of said drum, and certainadjacent connector tubes in the same transverse row being connected totube holes in different circumferential rows.

8. In a fluid heater, a drum, a bank of fluid heating tubes arranged inrows extending longitudinally and transversely relative to said drum, f

means connecting certain adjacent tubes in the same row, connector tubesconnecting said means with tube holes arranged in circumferential rowsspaced longitudinally of said drum a greater distance than thelongitudinal spacing of connector 5. In a fluid heater, a drum, a bankof fiuid relative to said drum, means separately connecting certainpairs of adjacent tubes in the same row, and connector tubes separatelyconnecting said means with tube holes arranged in circumferential rowsspaced longitudinally of said drum.

ISAAC HARTER.

